Project Summary/Abstract COVID-19, the infectious disease caused by SARS-CoV-2, is rapidly affecting humans around the globe. While initial epidemiological data have focused on cases that resulted in severe respiratory disease seen predominantly in adults, little information regarding the infection burden in children is available. This is complicated by the observation that many virologically-confirmed cases in children are asymptomatic. Home environments are established sources of exposure that exacerbate symptoms of asthma and home-based interventions are proven effective. Prior to the inception of the School Inner-City Asthma Study (SICAS-1), no American study had comprehensively evaluated the relationship between urban exposures in school, classroom, and home environments and asthma morbidity. Nearly all elementary school children spend 7 to 12 hours a day in school, and most of that time is spent in one classroom. From SICAS-1, we learned that student classroom-specific mouse allergen, mold, and particulate pollutant exposure is associated with worsening symptoms. We also demonstrated our ability to reduce these exposures in a busy, school setting. Our proposal builds upon our established, successful school-based infrastructure to determine whether a school/classroom intervention will efficiently and effectively improve asthma morbidity by reducing these exposures. Our goal is to determine the efficacy of school/classroom based environmental intervention in reducing asthma morbidity in urban schoolchildren. Our central hypothesis is that reducing classroom/school exposure to mouse allergen, mold, and particulate pollutants will decrease asthma morbidity in students with asthma. We plan to test this hypothesis in an intervention study of 250 elementary students with asthma from multiple classrooms in 40 Boston inner-city elementary schools. Our clinical trial aims are to determine the effectiveness of a school/classroom based environmental intervention (school integrated pest management and classroom air purifying filter units within these schools) to reduce asthma morbidity. The supplement to the parent grant is to leverage the cohort for the to participate in the multi-center survey entitled Human Epidemiology and Response to SARS-CoV-2 (HEROS), study. This study can be rapidly implemented and realistically conducted without necessitating any visits to a clinical research center. In addition to the need for surveying children for asymptomatic SARS-CoV-2 infection, this study will allow a comparison between children with asthma and other atopic conditions and children without those conditions through remote surveys and collection of samples. This study is an unprecedented, high impact opportunity to leverage the parent trial with in scope in understanding how SARS-C0V-2 differentially affects children with the condition of interest, compared to children without it.